Draft-regulator for furnaces



R. McCANN.

DRAFT REGULATOR FOR FURNACES.

APPLICATION FILED MAR. 10. I921.

1,3 0, Patent edJuno 7,1921.

2 SHEETS--SHEET l.

Fig.1. RobertM fiann R. MCCANN DRAFT REGULATOR FOR FURNACES.

APPLICA ION HLED MAR-10,1921.

Patented June 7, 1921.

2 SHEETS-SHEET 2,

'RabemM mmn @Q fi ROBERT MGCANN, 0F COL'UIWBUS, OHIO.

DRAFT-REGULATOR FOR FURNACES.

Specification of Letters Patent.

Patented June 7, 1921.

Application filed March 10, 1921. Serial No. 451,250.

To all whom it may concern:

Be it known that I ROBERT lE ICCANN, a citizen of the United states, residing at Golumbus, in the county of Franklin and State of Ohio, have invented a certain new and useful Improvement in Draft-Regulators for Furnaces, of which the following is a specification.

' The object of the present invention is to provide improved and very sensitive means I for automatically regulating the draft of a furnace so that the temperature of the house or building in which it is installed may be kept at a nearly uniform and desired degree. Other objects will appear from the disclosure herein.

The invention is embodied in the example herein shown and described the features of novelty being finally claimed.

In the accompanying drawings- Figure 1 is a general view in front elevation.

Fig. 2 is an elevation of a portion of the gpparatus looking at the right hand side of Fig. 3 is a detail in plan view of the controller on a larger scale.

Fig. 4 is a detail partly in section ofthe controller stop block operating rod Fig. 5 is a. detail partly in section of a.

portion coiiperating with the controller stop block.

In the views 6 designates a thermostatic bar or tube that extends through the hood of the furnace 7, said bar being rigidly held at its left hand end in a rigid frame 8 secured to the rafters 9 of the cellar. The

right hand end of the thermostatic bar is connected with an upstanding lever 10 pivoted inthe frame 8 so as to be oscillated by variations in the length of the thermostatic bar. The upper end of the lever 10 is in the form of a rounded tooth that engages a V-shaped notch in a block 11 on or engaged with the left hand end of a slightly flexible rod 12. The rod 12 and the block 11 are housed in a bar or frame formed with tubular portions 13 and 13% the block 11 working like a piston in the tubular portion 13. The block 11 is backed by a spring 14: that tends to keep the rod 12 abutted against the end of a set screw 15 in the outer end of the tubular portion 13 The tubular portion 13 extends through a block 16 supported rigidly upon a hanger 8 from the frame 8, said block 16 being recessed as shown at 16 Adjustably secured by set screw 17 to the tubular portion 13 where the latter crosses the space 16 is a stop 18, adapted to close the space between itself and one or the other of the opposed walls of the recess 16 according to the temperature of the thermostatic bar 6. One of these walls consists of an adjustable disk or plate 19 having a rounded edge and having, as shown in Fig. 5, a shank 20 provided on its opposite sides with unalined V-shaped notches 21 and 22 engaged by the tapered points of alined set screws 23 and 24 respectively so that by retracting one screw and advancing the other the disk or plate can be moved the distance desired to increase or diminish the space between it and the block 18. An important purpose of the disk 19 is to compensate for wear. Mounted on one end of a shaft 25 in the block 16 is a hub 26 having opposite but axially offset blades 27, said blades being positioned by set screws 26 so that when upon the shifting' of the block 18 the hub 26 is permitted to turn one blade will passthrough the space at one side of the block and the other will be stopped by the block 18 closing the other of said spaces. The other end of the shaft '25'has afiixed to it a grooved pulley 28 havis made of sufficient size to drive the shaft 25 and engender sufficient friction on the pulley to drive the shaft and operate the door and check while the weight 32 holds the. cord taut.

Connected with the wrist pin 29 is a chain 33 which is passed over a pulley 34 and connected with the draft door 35 of the furnace while a rod 33 is connected with the check valve 36 of the smoke pipe. A half of one revolution of the wrist pin causes the draft door to open and the check to close and the other half of such revolution of the pin causes the draft door to close and the check to open.

Pressing upon the upper side of the tubular portion 13 is a spring actuated pin 37 for the purposeof keeping thelever 1O engaged with the block 11. The reason for this and for the provision of the flexible rod 12 is to make allowance for occasional excessive expansion of the thermostatic bar 6. The V shaped engagement of the upper end or" the lever 1.0 and the block 11 permits some slipping of the engaging surfaces.

From the foregoing it Will be understood that a suilicient variation in the temperature in the hood of the furnace opens the space at one side of the block 18 and closes the other, and that the opening of the space at one side permits the blade 17 at that side to pass through said space, the rotation of the shaft 25 being arrested by the block 18 closing the space at the opposite side, hence as the temperature in the furnace hood rises and falls due to the alternate opening and closing of the damper and check the effect of the mechanism is to maintain in the building to be warmed a satisfactory uniform temperature. "The adiustability of the rod 152 permits adaptation of the apparatus to seasonal changes or so that the mean of temperature to be maintained may be varied. When the heavy Weight has run down and its power to operate the shaft exhausted because resting on the floor of the cellar it may. be restored to operative position by merely liiting it to a position near the illustrated in Figs. 1 and 2. In this operation the cord merely slips around the pulley Without effect by the pull of the small Weight 32.

The forms of the parts can be changed Without departing from the gist of the invention as claimed.

What I claim is:

1. in means for regulating the temperature of a furnace or the like having a draft controlling device, the combination of a thcrmostatic bar a stop block operated by said thermostatic bar, a rotary bladed member arranged to be released and arrested by said stop block and means for driving said bladed member and operating the draft controlling device.

2. In means for regulating the temperature of a furnace or the like having 'a draft controlling device, the combination of a thermostatic bar, adjustable means actuated by said bar, a stop block on said adjustable means, a rotary bladed member arranged to be released and arrested by said stop block and for driving said bladed member and operating the draft controlling device.

in ns for regulating the temperaace or the i be having a draft g device, the cor bmaticn of a therthermostatic bar, a rotary bladed arranged to be released and arsaid step block and means to driv- )laded member and operating the oiling device Y e I V ;"Hll'i1i[1{2,' the tempera furnace or the like having a draft controlling oevice, the combination of a thermostatic bar, a stop block actuated by said thermostatic bar, an adjustable Wall cooperating therewith, a rotary bladed member arranged to be released and arrested by said stop block and means for driving said bladed member and operating the draft controlling device.

5. in means for regulating the temperature of a furnace or the like having a draft controlling device, the combination of a thermostatic bar, a stop block operated by said thermostatic bar, a rotary bladed member arranged tobe released and arrested by said stop bloom, means for drivingsaid bladed 1 er iber, and means for actuating the draft controlling device having an eccentrlc connection with said blade drlvmg means.

ROBERT MOOANN.

i bar, an adjustable stop block actu 

